1. Field of the Invention
The present invention relates to a microfilm apparatus. More particularly the invention relates to a microfilm apparatus suited to a microfilm system designed to meet the needs of to an establishment requiring only a small amount of data to be recorded in microfilm form.
2. Description of the Prior Art
Recording of documents or other data has become comparatively common practice because of the advantages offered of economy of space required for storing records and of improved facility and lowered cost of transport of records, by post, for example. One type of known microfilm system employs a continuous roll of 16 mm. or 35 mm. film on which are produced the latent images of a succession of documents and which is subsequently processed and developed, to give one or more files of microfilm copies of documents. In another known microfilm system microfilm copies of a set of related documents are produced on a so-called microfiche film, which is a special type of film in the form of a sheet on which film frames are disposed in a rectangular array, for example a 5 .times. 12 array. Both these systems are essentially suited to organizations requiring large amounts of data to be stored in microfilm form. For a comparatively small office or other establishment in which it is occasionally required to microfilm a small number of documents at a time, for example twelve, the system employing microfiches is uneconomic, since for each microfilm film produced most of the frames on a microfiche are not used. There is liable to be similar waste with the system employing roll-film, particularly when it is required to immediately post microfilm copies of a set of documents. With the system employing roll-film it is of course possible to avoid wastage by not processing a roll of film until all the frames thereof have been exposed. However in this case, there is generally a problem of turnaround time, i.e., since the rate at which microfilm copies of documents are produced is low, microfilming a sufficient number of documents to use an entire roll of film extends over a long period, and there is therefore a long wait until microfilm copies carried by the initial frames of the film are obtained.
A further disadvantage of currently marketed conventional microfilm systems is that the associated apparatus generally requires comparatively skilled staff for actuation thereof. In a large establishment it is of course possible for there to be specialist staff employed in a microfilm department, but in a small establishment this is obviously uneconomical.
A microfilm apparatus suited to use in a small establishment is that disclosed in Japanese Patent Publication No. 49-91456, in which a roll of electrophotosensitive material is used as the microfilm material, successive frames of this material being electrically charged, exposed, and then developed in the apparatus. This apparatus has the advantage that production of only a small number of microfilm copies of documents at a time is permitted, but has the disadvantage that to permit the stages of charging, exposure and development to be kept separate it is necessary to allow a considerable space between adjacent frames of the film material, with the result that the number of microfilm copies obtainable from a roll of film material is limited, or the frames must be small. Another disadvantage is that since the power of resolution of currently known electrophotosensitive material is inferior to that of film material including a layer or layers of silver halide emulsion, the apparatus is generally unsuited to production of microfilm copies of drawings, or similar material. In addition to these disadvantages there is also the disadvantage that initial cost and cost of maintenance of the equipment are high.
It is accordingly object of the present invention to provide a microfilm apparatus which is compact, easy to maintain, and suited to employment in a small office or similar establishment.
It is another object of the invention to provide a microfilm apparatus which employs film material including a layer of silver halide emulsion thereby making it possible to obtain microfilm copies of high resolution, which makes it possible to produce independent sets of a few microfilm copies of documents at a time, and which may be easily actuated by non-specialist staff.
A further object of the invention is to provide a microfilm apparatus which includes an exposure compartment for production of latent images on film material and a development and processing compartment for immediate development and processing of a set of exposed film frames, and which comprises means for sealing the exposure compartment to vapours produced during development of film, whereby corrosion of said processing compartment is prevented.